Make Datapack Registries support ICondition(s) (#9113)

src/main/java/net/minecraftforge/common/ForgeHooks.java

@@ -8,6 +8,7 @@ package net.minecraftforge.common;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.util.*;
+import java.util.Map.Entry;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Function;
@@ -27,6 +28,7 @@ import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import com.google.gson.JsonParseException;
 import com.mojang.serialization.Codec;
+import com.mojang.serialization.JsonOps;
 import com.mojang.serialization.Lifecycle;
 
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
@@ -107,6 +109,7 @@ import net.minecraft.world.level.biome.Biome;
 import net.minecraft.world.level.biome.BiomeSpecialEffects;
 import net.minecraft.world.level.biome.BiomeGenerationSettings;
 import net.minecraft.world.level.biome.MobSpawnSettings;
+import net.minecraftforge.common.crafting.conditions.ICondition;
 import net.minecraftforge.common.loot.IGlobalLootModifier;
 import net.minecraftforge.common.loot.LootModifierManager;
 import net.minecraftforge.common.loot.LootTableIdCondition;
@@ -171,8 +174,10 @@ import org.apache.logging.log4j.Marker;
 import org.apache.logging.log4j.MarkerManager;
 
 import net.minecraft.ChatFormatting;
+import net.minecraft.resources.RegistryResourceAccess;
 import net.minecraft.resources.ResourceKey;
 import net.minecraft.resources.ResourceLocation;
+import net.minecraft.resources.RegistryResourceAccess.EntryThunk;
 import net.minecraft.world.damagesource.DamageSource;
 import net.minecraft.world.level.GameType;
 import net.minecraft.world.level.Level;
@@ -1660,4 +1665,12 @@ public class ForgeHooks
         }
         return false;
     }
-}
+
+    @SuppressWarnings("unchecked")
+    public static <E> Collection<Entry<ResourceKey<E>, EntryThunk<E>>> filterThunks(Map<ResourceKey<E>, RegistryResourceAccess.EntryThunk<E>> map)
+    {
+        return map.entrySet().stream().filter(e -> 
+        ((EntryThunk<Boolean>)e.getValue()).parseElement(JsonOps.INSTANCE, ICondition.DECODER)
+        .get().left().get().value()).toList(); // Validity of this .get() call is enforced by the above Decoder object, which only returns DataResult.success.
+    }
+}

src/main/java/net/minecraftforge/common/crafting/CraftingHelper.java

@@ -234,4 +234,14 @@ public class CraftingHelper
             throw new JsonSyntaxException("Unknown condition type: " + condition.getID().toString());
         return serializer.getJson(condition);
     }
+
+    public static JsonArray serialize(ICondition... conditions)
+    {
+        JsonArray arr = new JsonArray();
+        for(ICondition iCond : conditions)
+        {
+            arr.add(serialize(iCond));
+        }
+        return arr;
+    }
 }

src/main/java/net/minecraftforge/common/crafting/conditions/ICondition.java

@@ -5,11 +5,17 @@
 
 package net.minecraftforge.common.crafting.conditions;
 
+import com.google.gson.JsonObject;
+import com.mojang.datafixers.util.Pair;
+import com.mojang.serialization.DataResult;
+import com.mojang.serialization.Decoder;
+import com.mojang.serialization.DynamicOps;
 import net.minecraft.core.Holder;
 import net.minecraft.core.Registry;
 import net.minecraft.resources.ResourceKey;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.tags.TagKey;
+import net.minecraftforge.common.crafting.CraftingHelper;
 
 import java.util.Collection;
 import java.util.Collections;
@@ -18,6 +24,28 @@ import java.util.Set;
 
 public interface ICondition
 {
+
+    Decoder<Boolean> DECODER = new Decoder<>() {
+        @Override
+        public <T> DataResult<Pair<Boolean, T>> decode(DynamicOps<T> ops, T input)
+        {
+            if(input instanceof JsonObject obj && obj.has("forge:conditions"))
+            {
+                try
+                {
+                    boolean result = CraftingHelper.processConditions(obj, "forge:conditions", IContext.TAGS_INVALID);    
+                    return DataResult.success(Pair.of(result, input));
+                } 
+                catch(Exception ex)
+                {
+                    ex.printStackTrace();
+                    return DataResult.success(Pair.of(false, input)); // Print stacktrace and do not load errored conditions.
+                }
+            }
+            return DataResult.success(Pair.of(true, input));
+        }
+    };
+
     ResourceLocation getID();
 
     boolean test(IContext context);
@@ -33,6 +61,15 @@ public interface ICondition
             }
         };
 
+        IContext TAGS_INVALID = new IContext()
+        {
+            @Override
+            public <T> Map<ResourceLocation, Collection<Holder<T>>> getAllTags(ResourceKey<? extends Registry<T>> registry)
+            {
+                throw new UnsupportedOperationException("Usage of tag-based conditions is not permitted in this context!");
+            }
+        };
+
         /**
          * Return the requested tag if available, or an empty tag otherwise.
          */

src/main/java/net/minecraftforge/common/data/JsonCodecProvider.java

@@ -8,9 +8,11 @@ package net.minecraftforge.common.data;
 import com.mojang.logging.LogUtils;
 import java.io.IOException;
 import java.nio.file.Path;
+import java.util.Collections;
 import java.util.Map;
 
 import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
 import com.mojang.serialization.Codec;
 import com.mojang.serialization.DynamicOps;
 import com.mojang.serialization.JsonOps;
@@ -26,6 +28,8 @@ import net.minecraft.resources.RegistryOps;
 import net.minecraft.resources.ResourceKey;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.packs.PackType;
+import net.minecraftforge.common.crafting.CraftingHelper;
+import net.minecraftforge.common.crafting.conditions.ICondition;
 import net.minecraftforge.common.data.ExistingFileHelper.ResourceType;
 import org.slf4j.Logger;
 
@@ -49,6 +53,7 @@ public class JsonCodecProvider<T> implements DataProvider
     protected final String directory;
     protected final Codec<T> codec;
     protected final Map<ResourceLocation, T> entries;
+    protected Map<ResourceLocation, ICondition[]> conditions = Collections.emptyMap();
 
     /**
      * @param dataGenerator DataGenerator provided by {@link GatherDataEvent}.
@@ -112,6 +117,18 @@ public class JsonCodecProvider<T> implements DataProvider
             final Path path = outputFolder.resolve(String.join("/", dataFolder, id.getNamespace(), this.directory, id.getPath() + ".json"));
             JsonElement encoded = this.codec.encodeStart(this.dynamicOps, value)
                   .getOrThrow(false, msg -> LOGGER.error("Failed to encode {}: {}", path, msg));
+            ICondition[] conditions = this.conditions.get(id);
+            if (conditions != null && conditions.length > 0) 
+            {
+                if(encoded instanceof JsonObject obj)
+                {
+                    obj.add("forge:conditions", CraftingHelper.serialize(conditions));
+                }
+                else
+                {
+                    LOGGER.error("Attempted to apply conditions to a type that is not a JsonObject! - Path: {}", path);
+                }
+            }
             DataProvider.saveStable(cache, encoded, path);
         }));
     }
@@ -126,4 +143,16 @@ public class JsonCodecProvider<T> implements DataProvider
     {
         return String.format("%s generator for %s", this.directory, this.modid);
     }
+
+    /**
+     * Applies a condition map to this provider.
+     * These conditions will be applied to the created JsonElements with the matching names.
+     * Null or empty arrays will not be written, and if the top-level json type is not JsonObject, attempting to add conditions will error.
+     * @param conditions The name->condition map to apply.
+     */
+    public JsonCodecProvider<T> setConditions(Map<ResourceLocation, ICondition[]> conditions)
+    {
+        this.conditions = conditions;
+        return this;
+    }
 }